Get rid of that fake powder and get some balck powder...hence the name...black powder rifle. Flinters are very fussy to begin with. Why tempt fate by using anything less.
Also good advise above on flint positioning. Some like it flat up, others flat down. Don't worry about the "geometry" of hammer strike vs face of the frizzen...manufacturers have it in the ballpark and it ahould work fine. Besides, most folks that start bending parts to fit usually dork it up beyond repair.
There is only one secret to flintlocks...FLINTS! Buy the best and guard them with your life. I've had flints that were done after 10 shots. I now get almost 100 shots per rock and have one flint that went over 150 shots! The secret is in the rock.
I always recommend using the same powder for priming that you use for loading. There is no reason it should not work. I use 2f for priming and loading on my .72 and 3f on the .34 without issue. Both guns are fast beyond belief.
I had my.72 relined with a new touch hole liner and opened it up to 1/16" ....that really helped. I don't advocate plugging the touch hole while loading. As a matter of fact, I usually have a couple flecks of powder drop into the pan when dropping the main charge. That powder is kissed right up against the hole ready for any spark to light it up! And boy, that gun is very fast!!!!!
Priming the pan. Just a couple of grains should do it. Most folks over prime A LOT. You only need about 1/4 of the pan full. If overfull, the flame jumps too high, missing the touch hole and causing misfires.
Hope this helps and never give up!
Again, welcome aboard!